The goal of our proposed research is to provide a structural and biochemical account of the activities of Glugea parasites during growth within greatly hypertrophied host cells (xenomas). The ultimate goal is to identify the mechanisms by which these intracellular parasites alter host cell development and induce growth; in addition, we wish to determine what physiological principles enable these intracellular parasites to multiply to large numbers without causing host cell degeneration. It is likely that we can gather some important information about the general phenomenon of induced cell hypertrophy caused by this peculiar group of intracellular parasites since we have access to techniques which will enable us to deal with the endoparasites independently of the host cells. Information on the molecular activities of the parasites and the host cells will be characterized by isotopic labels, spectrophotometric analysis, chromatography and electron microscopy.